Year Percent change (Units) 1993 31.930 1994 20.872 1995 13.572 1996 9.919 1997 8.342 1998 7.948 1999 6.121 2000 8.935 2001 8.380 2002 7.481 2003 5.544 2004 3.593 2005 2.452 2006 2.458 2007 3.657 2008 5.647 2009 0.839 2010 1.801 2011 1.803 2012 2.597 2013 1.769 2014 0.199 2015 -0.526 2016 -0.055 2017 1.429 2018 1.739 2019 1.631 2020 -0.055 2021 1.917 2022 8.834 2023 7.447 2024 2.733 2025 1.968 2026 2.033 2027 2.012 2028 2.004 2029 2.004